51631121 has 4 divisors (see below), whose sum is σ = 51645552. Its totient is φ = 51616692.

The previous prime is 51631061. The next prime is 51631127. The reversal of 51631121 is 12113615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51631121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51631093 and 51631102.

It is not an unprimeable number, because it can be changed into a prime (51631127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2630 + ... + 10496.

It is an arithmetic number, because the mean of its divisors is an integer number (12911388).

Almost surely, 2^51631121 is an apocalyptic number.

It is an amenable number.

51631121 is a deficient number, since it is larger than the sum of its proper divisors (14431).

51631121 is an equidigital number, since it uses as much as digits as its factorization.

51631121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14430.

The product of its digits is 180, while the sum is 20.

The square root of 51631121 is about 7185.4798726320. The cubic root of 51631121 is about 372.3664274928.

Adding to 51631121 its reverse (12113615), we get a palindrome (63744736).

The spelling of 51631121 in words is "fifty-one million, six hundred thirty-one thousand, one hundred twenty-one".